PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago
with promise that one day it will be possible to implement page cache with
bigger chunks than PAGE_SIZE.

This promise never materialized. And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_*
or PAGE_* constant should be used in a particular case, especially on the
border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special. They are not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
Cc: Russell King <li...@arm.linux.org.uk>
---
 arch/arm/mm/flush.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index d0ba3551d49a..3cced8455727 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -235,7 +235,7 @@ void __flush_dcache_page(struct address_space *mapping, 
struct page *page)
         */
        if (mapping && cache_is_vipt_aliasing())
                flush_pfn_alias(page_to_pfn(page),
-                               page->index << PAGE_CACHE_SHIFT);
+                               page->index << PAGE_SHIFT);
 }
 
 static void __flush_dcache_aliases(struct address_space *mapping, struct page 
*page)
@@ -250,7 +250,7 @@ static void __flush_dcache_aliases(struct address_space 
*mapping, struct page *p
         *   data in the current VM view associated with this page.
         * - aliasing VIPT: we only need to find one mapping of this page.
         */
-       pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+       pgoff = page->index;
 
        flush_dcache_mmap_lock(mapping);
        vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
-- 
2.7.0

Reply via email to